Handheld computing devices, such as personal digital assistants and pocket PCs, provide a convenient platform for communicating with diagnostic instrumentation. The portability and flexibility of a handheld computing device enables a technician to use a diagnostic instrument quickly and easily. For example, in an automotive service facility, a handheld computing device can be easily coupled to a vehicle's on-board diagnostic system for testing or problem diagnosis.
Conventionally, handheld computing devices include touch sensitive display screens that are operated with a stylus. The stylus typically has a polished or smooth plastic end that is designed to contact the display screen surface. A typical software user interface requires a user to tap the stylus on the appropriate screen element to navigate through various menu bar options or icon selections. Further, the stylus may be needed to enter data, such as customer information, into the handheld computing device.
One problem with using a stylus in a vehicle service facility or other harsh environment is that the stylus can be easily misplaced. Because the icons, menu bar, or other screen elements in a conventional user interface require a relatively small contact area to function properly, operating the device without a stylus can be challenging. In the interest of being able to use the device without a stylus, a technician could substitute another handy shop item such as a sharp screw or screwdriver for the blunt tip stylus. Of course, the plastic screen of the handheld computing device is not designed to be contacted with sharp instruments and can become damaged accordingly.
Further, service facility technicians commonly wear hand protection that can make using the stylus cumbersome. A handheld computing device typically has a small groove in which the stylus is stored. Even if the stylus is not lost and is properly stored in the device, a technician wearing work gloves may find it difficult to retrieve and to use the stylus. Additionally, the technician may find it difficult to replace the stylus into the small groove—a condition which worsens the problem of misplacing the stylus.
What is needed is a user interface for a handheld computing device that can provide functionality without the continuous use of a stylus or similar pointing device. What is further needed is a system and method for operating a diagnostic instrument using the user interface.